Making Homemade Cultured Dairy
This information on homemade cultured dairy includes buttermilk, cottage cheese, sour cream, yogurt, Crème Fraîche, and Mexican crema. These can be made if you have access to buttermilk, sour cream, or yogurt with live cultures from the grocery store. Cultures can also be bought from cheese making stores including several on the Internet. These dairy products do not require using rennet, although several sources say that some adding rennet makes a better product.
Exceptions to this include cheeses such as queso fresco or queso blanco (traditionally eaten in Latin American countries) and paneer (traditionally eaten in India), which are made without bacterial cultures or rennet. These cheeses are made using what is called acid coagulation by curdling hot milk by adding an acid such as vinegar or fruit juice (like lemon juice). This type of fresh cheese is simple to make and has a higher yield because all the whey proteins normally lost are included in the cheese.
There are also other dairy products such as clotted cream that requires no cultures or acid added, but are made by heating cream.
How to Culture Dairy and Ferment Milk
The process of cheesemaking requires the ripening or culturing of milk. Cheesemaking techniques vary depending on the intended final use or consumption of the cheese. Cheese has widely varying characteristics. Cheese can be defined as a curd formed by concentrating the protein and fat in milk. Making cheese is a dynamic process that is affected by time, temperature, and the bacterial culture (lactic acid bacteria) and coagulating enzyme (rennet) that are used to concentrate and separate the casein (milk protein) and fat from the whey.
To make fermented dairy foods, you'll need two basic ingredients. Milk and a source of beneficial bacteria. That's it. You can use any type of milk. Whole, low-fat, and even skim milk work for most fermented milk products. Central to the production of cultured milk is the initial fermentation process, which involves the partial conversion of lactose (milk sugar) to lactic acid. Lactose conversion is accomplished by beneficial bacteria, such as lactic-acid–producing Streptococcus thermophilus and Lactobacillus bulgaricus. The discharged liquid, a yellowy liquid known as whey, contains most of the water, lactose, simple proteins, minerals, and vitamins. The two most common and readily used cultures are mesophilic and thermophilic.
For most cultured dairy foods, you'll use a starter culture or mother culture. These dairy cultures contain live active bacteria. These are contained in many foods bought at the grocery store. For example, Fage Total 5% Greek Yogurt contain these ingredients: Grade A Pasteurized Skimmed Milk and Cream, Live Active Yogurt Cultures (L. Bulgaricus, S. Thermophilus, L. Acidophilus, Bifidus, L. Casei). If you use dairy foods from the grocery store for cultures, be sure the label says "live cultures" and determine which cultures are contained in the product.
While some cheese and other dairy products can be made from lower fat dairy, it is important to consider that the flavor, texture, and moisture content of a cheese made from low-fat milk will be much different than a cheese product with a higher fat content.
The most important factor to keep in mind is that everything needs to be perfectly clean so you don’t invite any unwanted bacteria into your mix.
Time and Temperature
Once you've added the bacterial culture to your milk, you simply need to wait. Some forms of cultured milk depend on warm temperatures, while others benefit from culturing at room temperature. For those foods, such as yogurt, that need warmth to culture correctly. So you'll add the starter to warm milk. While others, such as kefir, work well by adding the starter directly to cold milk and letting it ferment at room temperature. When it's done, and pleasantly sour, you'll transfer it to the fridge for cold storage.
The fermentation time varies depending on the individual recipe and which fermented milk product you're making. Yogurt, for example, typically ferments within about 4 to 6 hours while kefir can take 1 to 2 days. Most varieties of cheese will need to age much longer, but fresh cheeses such as cream cheese and chèvre have a shorter fermentation period.
Milk and Cream used for Fermentation
In the United States, uncultured milk and cream is usually sold with these percentages of milk fat. This information is useful for determining which dairy product to use when making home made cultured dairy products. You should also note that ultra pasterized milk or cream do NOT work well for making cultured dairy products.
Whole Milk (about 3.5% fat)
Half and half (10.5–18% fat)
Light, coffee, or table cream (18–30% fat)
Medium cream (25% fat)
Whipping or light Whipping cream (30–36% fat)
Heavy Whipping cream (36% or more)
Extra-heavy, double, or manufacturer's cream (38–40% or more)
Mesophilic vs Thermophilic Fermentation
Mesophilic means medium-temperature loving bacteria which will ferment the best at temperatures up to 30°C or 90°F.
Thermophilic is a heat-loving bacteria which will ferment best when above 30°C or 90°F.
Mesophilic cultures, used for making buttermilk, sour cream, Mexican crema and Crème Fraîche, do their work at room temperature; as opposed to Thermophilic cultures used for making most store-bought yogurts and which requires a warmer environment.
The difference in the dairy product is the amount of milk fat in the dairy used for fermenting. For instance, the bacteria in the buttermilk or sour cream when added to milk produce a cultured buttermilk. By adding the same bacteria to cream, the culture produces sour cream.
Buttermilk (1–2% milkfat) - whole, 2%, or skim milk
Sour Cream (14–18% milkfat) - light cream, 18–30% milkfat
Crème Fraîche (30-40% milkfat) - heavy cream, 36 % or more milkfat
Mexican crema (30% milkfat) - whipping cream, around 36 % milkfat
Yogurt (0.5–4% milkfat) - whole milk yields a higher milkfat content
Mesophilic Cultures: Normally, souring is achieved by inoculation with mesophilic lactic acid bacteria. The most common mesophilic cultures comprise Lactococcus lactis subsp. lactis, Lc. lactis subsp. cremoris, citrate-positive strains of lactococci, and Leuconostoc mesenteroides subsp. cremoris. Lactobacillus acidophilus plays an important role, owing to its perceived health benefits. Both buttermilk and sour cream are made using Mesophilic fermentation. Sour cream is made according to the same temperature and culture methods as used for buttermilk. The main difference is the starting material—sour cream starts with light 18 percent cream.
Note: If you can use either sour cream (with active cultures) or buttermilk (with active cultures) as a Mesophilic starter. Look at the various labels on buttermilk and sour cream containers, you will find that both the buttermilk and sour cream starters contain the same four cultures: Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Lactococcus lactis biovar diacetylactis and Leuconostoc mesenteroides subsp. cremoris. Be sure the container says the product contains live cultures.
Thermophilic Cultures: Yogurt is made in a similar fashion to buttermilk and sour cream, but it requires different bacteria and temperatures. When making yogurt, whole, low-fat, or skim milk is fortified with nonfat dry milk or fresh condensed skim milk, in order to raise the total solids to 14 to 16 percent. The mixture is heat-treated and then cooled to 45.6 to 46.7 °C (114 to 116 °F). At this point a culture of equal parts Lactobacillus bulgaricus and Streptococcus thermophilus is added to the warm milk. (Many yogurt manufacturers have added Lactobacillus acidophilus to their bacterial cultures. L. acidophilus has possible health benefits in easing yeast infections and restoring normal bacterial balance to the intestinal tract of humans after antibiotic treatment.) The temperature of the fermenting yogurt is then kept in the heat range of about 105 to 115 degrees for about 5 hours (or more if desired).
From Wikipedia:
| Product | Main Ingredients | Typical milkfat content | Typical shelf life at 4 °C | Fermentation agent | Description |
| Cheese | 1-75% | varies | a variety of bacteria or mold | Any number of solid fermented milk products. | |
| Cultured buttermilk | Milk, buttermilk or sour cream w/ live cultures | 1–2% | 10 days | Lactococcus lactis* (subsp. lactis*, subsp. cremoris**, biovar. diacetylactis), citrate-positive strains of lactococci, and Leuconostoc mesenteroides subsp. cremoris |
Mesophilic fermented pasteurized milk |
| Cultured sour cream | Heavy cream, buttermilk or sour cream w/ live cultures | 14–40% | 4 weeks | Lactococcus lactis subsp. lactis* | Mesophilic fermented pasteurized cream with an acidity of at least 0.5%. Rennet extract may be added to make a thicker product. Lower fat variant of crème fraîche |
| Mexican Crema | Whipping cream, buttermilk or sour cream w/ live cultures | about 30% | Made using the same Mesophilic cultures as buttermilk and sour cream. | ||
| Crème fraîche | 30-40% | 10 days | naturally occurring lactic acid bacteria in cream | Mesophilic fermented cream, originally from France; higher-fat variant of sour cream | |
| Yogurt | 0.5–4% | 35–40 days | Lactobacillus bulgaricus and Streptococcus thermophilus | Thermophilic fermented milk, cultured with Lactobacillus bulgaricus and Streptococcus thermophilus |
*Streptococcus lactis has been renamed to Lactococcus lactis subsp. lactis
**Streptococcus cremoris has been renamed to Lactococcus lactis subsp. cremoris
***Streptococcus diacetylactis has been renamed to Lactococcus lactis subsp. lactis biovar. diacetilactis
The only ‘dairy streptococci’ remaining from those originally described by Sherman over 60 years ago is Streptococcus thermophilus.
Buttermilk - 1–2% milk fat
Despite its name and creamy consistency, buttermilk is relatively low in fat. Most modern buttermilk is cultured buttermilk, made from low-fat or skim milk and has less than 2 percent fat. It is prepared by fermentation with bacteria that produces lactic acid, which gives the milk a slightly sour taste and makes it easier to digest by lactose-intolerant consumers. The resulting product is thicker than traditional buttermilk, the whey left from churning butter.
The starting ingredient for making buttermilk is skim or low-fat milk. The milk is pasteurized at 82° to 88° C (180° to 190° F) for 30 minutes, or at 90° C (195° F) for two to three minutes. This heating process is done to destroy all naturally occurring bacteria and to denature the protein in order to minimize wheying off (separation of liquid from solids). Milk purchased from the grocery store is already pasteurized and does not have to go through this heating phase.
The milk is then cooled to 22° C (72° F), and starter cultures of desirable bacteria, such as Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Leuconostoc citrovorum, and L. dextranicum, are added to develop buttermilk's acidity and unique flavour. These organisms may be used singly or in combination to obtain the desired flavour.
The ripening process takes about 12 to 14 hours (overnight). At the correct stage of acid and flavour, the product is gently stirred to break the curd, and it is cooled to 7.2° C (45° F) in order to halt fermentation.
Sour cream and buttermilk depend for their flavor on the combined action of strains of Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris to produce lactic acid and on Leuconostoc mesenteroides subsp. cremoris and citrate-positive (Cit+) strains of Lactococcus lactis for production of aroma chemicals (especially diacetyl). In recent years, some dairies have stopped using Cit+ Lactococcus lactis subsp. lactis biovar diacetylactis because it generates a rather harsh flavor profile.
Lactic acid imparts a pleasant acid flavor. Excessive lactic acid from over-ripening or improper incubation temperature (or delayed cooling/under-cooling) makes the finished product taste acrid and gives it a coarse mouthfeel. Furthermore, excessive acidity masks the delicate flavor notes contributed by other important aroma chemicals. Only about 18% of the naturally available lactose in milk is fermented to lactic acid. The desired lactic acid level in good-flavored buttermilk is 0.75%–0.85%.
Yogurt - 0.5–4% milk fat
Ready-made yogurts are made from whole milk (with up to 4% butterfat), lowfat milk (with up to 2% butterfat), and skim milk (with up to .5% butterfat). Yogurt, a medium-acid fermented milk, is fermented by symbiotic cultures of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus characterized by a smooth, viscous gel with a delicate walnutty flavor. The two yogurt bacteria reside either naturally in the milk (in the regions where yogurt is traditionally made) or are added as starter cultures. The new yogurts often contain Bifidobacteria. Bifidobacteria are a group of bacteria called probiotics that normally live in your intestines and stomach.
In many countries (e.g., Sweden, France, Belgium, Portugal, Spain, USA) legislation exists allowing only L. bulgaricus and S. thermophilus to be used to produce yogurt. In the UK yogurt can be made using both of these strains or just one of them. In other countries (e.g., Switzerland) strains such as L. acidophilus and bifidobacteria may be used in addition to the traditional yogurt strains.
Yogurt goes through two primary stages of production: heating and fermentation. The heating process requires milk be heated to at least 185F/85C for 30 minutes or at 195F/90C for 10 minutes. This causes the various proteins and fats to bond together in a complex chain as opposed to blobs here and there floating in a liquid. The fermentation stage is where bacterial cultures are added and the yogurt is kept in a warm environment around 114 to 116 °F. The milk begins to thicken even more and sour intensely. Due to the protein matrix developed, this ingredient does not separate when allowed to sit.
Concentrated yogurt, strained yogurt, labneh, or Greek yogurt is yogurt that has been strained in a cloth or paper bag or filter to remove the whey. It has a consistency between that of yogurt and cheese, and yogurt's distinctive sour taste. It is a traditional food in the Levant, Eastern Mediterranean, Near East, and South Asia, where it often is used in cooking preparations, as it is high enough in fat not to curdle at higher temperatures.
Traditional Yogurt Culture from Cultures for Health website: Lactose, Lactic Bacteria (S. thermophilus, L. delbrueckii subsp. bulgaricus, L. acidophilus, Bifidobacterium lactis)
Recipe for making Homemade Yogurt
Sour Cream - 14–18% milk fat
In German supermarkets, sour cream is typically made from 10% fat cream, but in principle, it can be made with other grades of cream. American sour cream is heavier-bodied than its European counterpart and has a higher fat content.
Sour cream, also known as cultured cream, is produced by the fermentation of high-pasteurized cream that contains 18–20% fat content. It is then homogenized at a low temperature, to promote formation of homogenization clusters. The starter cultures typically used for making sour cream contain aromatic starters (i.e., Lc. lactis subsp. lactis biovar. diacetylactis and L. mesenteroides subsp. cremoris) similar to those used for cultured buttermilk. As lactic acid is produced by the bacteria, the homogenization clusters aggregate, resulting in highly viscous cream. However, to increase the firmness further, a little rennet and/or a thickening agent, such as dry milk powder, are sometimes added before the inoculation of starter cultures. To thicken homemade sour cream, heat the cream to 180ºF and hold for 30 minutes. Cool completely before adding the starter culture.
Sometimes store-bought sour cream is cultured. However, not all of them are, so you will need to read the label. Still, store-bought sour cream is generally not a very vigorous culture, so give it a full 24 hours the first time you use it to make homemade sour cream. Cultured buttermilk can be used as starter culture to produce sour cream as they both use the same Mesophilic cultures. A substitute and very good-tasting soured cream can be made using yogurt or kefir as starter instead, but it's not really what we think of as sour cream, and is not as thick.
Like all fermented cultures, sour cream needs to be fed regularly to remain healthy and vigorous. Realistically, that means making sour cream once a week! However, dairy cultures freeze very well. Here’s how to freeze sour cream culture for future batches: Whenever you make sour cream, freeze enough culture for the next batch. It will last in the freezer for at least 4 weeks (and up to several months). Defrost the frozen culture for 24 hours in the fridge before using it.
Traditional Sour Cream Culture from Cultures for Health website: Lactic Bacteria (L. lactis subsp. lactis, L. lactis subsp. cremoris, L. lactis subsp. biovar, lactis biovar, Diacetylactis, Leuconostoc mesenteroides subsp. cremoris)
Crème Fraîche - 30-40% milk fat
A standard fare in France, crème fraîche is a thick, rich cultured cream, used much like sour cream. It makes a delicious topping for soups, main dishes and even desserts. The decadent texture is rich, creamy, and very satisfying.
Crème Fraîche is less sour than sour cream. It has at least 30% fat and is made with a special strain of mesophilic cultures. While they are often used interchangeably in recipes, sour cream contains about 20% butterfat and has a sour flavor whereas crème fraîche has more butterfat and a milder flavor.
Crème fraîche can be made easily at home, using a couple of different starter cultures.
The first step to making crème fraîche is choosing an appropriate cream for the project. Whipping cream (whole cream) will yield the thickest crème fraîche. Half-and-half can be used, but the crème fraîche will have a thinner consistency. Dry milk powder can be added as thickener, if desired.
According to https://www.masterclass.com/, the difference between making sour cream and crème fraîche has to do with the amount of starter used and the time it is left to ripen: “You can make your own crème fraîche at home by combining one cup heavy whipping cream with one tablespoon buttermilk in a glass jar and leaving at room temperature (72°F to 78°F) for 12 to 24 hours. For sour cream, increase the amount of buttermilk to a quarter cup and leave to ripen for 24 to 48 hours. Refrigerate at least one day before serving.”
Recipe for making homemade Crème Fraîche.
Mexican Crema - about 30% milk fat
Mexican Crema is a creamy and slightly tangy condiment very similar to sour cream. It’s thicker and richer than American sour cream, but not as thick and rich as French crème fraîche. It’s often used as a finishing touch to Mexican dishes like tacos, enchiladas and mixed into soups. In addition to adding great flavor, it also helps tone down the heat and spiciness of chiles used in Mexican cuisine.
Sour cream has a fat content of about 20%, is a bit more acidic in flavor and is fairly thick. It also tends to curdle easily when used in hot preparations. Mexican crema has a higher fat content of about 30%, isn’t quite as sour and is a lot thinner. It doesn’t curdle which makes it perfect for mixing into hot dishes and adding some richness.
Crema is made using the same Mesophilic cultures as buttermilk and sour cream.
See Crema (Mexican Sour Cream) for information for making your own homemade Crème Fraîche.
